R1:b262ccdaff31

Use ApplicationSearch to power primary search

Summary:
Ref T4365. Drive primary search through ApplicationSearch instead of through a bunch of custom nonsense. Notably, this allows you to save searches, notably.

The one thing this doesn't do -- which I'd like it to -- is carry your query text across searches. When you search for "quack", I want to overwrite the query in your default filter and give you those results, so you can turn the search into an "Open Tasks" search by default by reordering the…